Regression analysis in SPSS

Hi guys, I have a question about a formula for the SPSS program. It's about my thesis for determining the Halloween and January Effects.

Yt = A + β · Dt + Et

The Yt of this formula illustrates the variable of the regression model to be explained. This variable is represented by the constant alpha and the regression coefficient beta. Both alpha and beta (β) are determined using regression analysis. Eta (Et) functions in this context as a disturbance term variable, which can lead to a possible degradation within the regression model. Delta (Dt) has its function as a dummy variable for the Halloween effect in the above formula. The dummy variable indicates a value of 1 for the period from November to April and a value of 0 for the months from May to October.